In association with a daily increase in the amount of existing information, information is processed by computers more and more. When information is processed by a computer, a keyboard is ordinarily provided as an input section and information is inputted by key operations. Or, in some large-sized computers, information is input by voice, using speech recognition techniques.
In recent years, use of small-sized personal computers has become generally widespread. However, it is difficult for general operators to remember the positions of the keys of the keyboard and to learn the input operations of the keys, so that it is troublesome to use the personal computer. Therefore, in order to make input operations and use easy, the voice input approach is considered. To properly recognize speech, large amounts of waveform patterns and dictionary data conventionally need to be stored. However, there are limitations of memory capacity and processing speed in the case of a small-sized personal computer, so that it is difficult to realize the speech recognition necessary for voice input.